Fans in gas turbine engines are complex rotating systems that may encounter undesirable conditions during normal operation. Fans may be subject to debris entering an engine inlet. The debris may contact the blades of the fan and cause structural damage. As the use of composite materials for fan blades has become more prevalent, so too has the risk of delamination and fiber breakage.
Fan blades are typically designed to have a light weight while maintaining sufficient strength to absorb impacts. Many composite blades are made using a resin transfer molding (RTM) process. The typical RTM process for fan blades uses two-dimensionally woven plies, three-dimensional preforms, or both. These plies and preforms are costly to make and use complex weaving machines. The carbon fibers in the plies and preforms may not be optimally oriented as there is little ability to customize fiber orientation to accommodate loads on a blade.